Pump processes that produce upconversion laser emission in trivalent rare earth ion-doped gain media are described, and the performance of upconversion lasers pumped by these processes is reviewed. Sequential two-photon absorption upconversion, cooperative energy transfer upconversion and photon avalanche upconversion are discussed in relation to the production of visible laser emission. Using ...

Gap tips prepared f ran whiskers grown by the vapour phase reaction, were analyzed using our ctmbined-type atom-probe FIM by laser pulse operation instead of high voltage pulse operation. It was found that ( 1 ) The mposition is Ga : P=l : l at cryogenic temperature 45K in vacuum of better than 1 x 10-Ptorr. ( 2 ) Much more cluster ions of phosphorus atan in laser pulse mode are detected in can...

We studied proton beam production from a laser ion source using hydrogen rich target materials. In general, gas based species are not suitable for laser ion sources since formation of a dense laser target is difficult. In order to achieve reliable operation, we tested hydride targets using a sub nanosecond Q-switched Nd-YAG laser, which may help suppress target material consumption. We detected...

This study explains the breakdown mechanism in different triggered spark gap switches. Two different trigger electrode configurations are tested for the switch predischarge operation in a nitrogen laser circuit. The behavior of the breakdown voltage, when a trigger pulse is applied to the trigger electrode, is investigated, and the results are reported. Based on the experimental measurements ne...

We propose and experimentally demonstrate a continuous wave (CW) tunable-wavelength fiber laser using self-seeding Fabry-Perot laser diode (FP-LD) without optical amplifier inside gain cavity. By employing a tunable bandpass filter (TBF) and a fiber reflected mirror (FRM) within a gain cavity, the fiber laser can lase a single-longitudinal wavelength due to the self-seeding operation. The propo...

The acronymLASER, constructed fromLightAmplification byStimulatedEmission of Radiation, has become so common and popular in every day life that it is now referred to as laser. Fundamental theories of lasers, their historical development from milliwatts to petawatts in terms of power, operation principles, beam characteristics, and applications of laser have been the subject of several books [1–...

We report the demonstration of a diode-pumped chirped pulse amplification Yb:YAG laser that produces λ=1.03  μm pulses of up to 1.5 J energy compressible to sub-5 ps duration at a repetition rate of 500 Hz (750 W average power). Amplification to high energy takes place in cryogenically cooled Yb:YAG active mirrors designed for kilowatt average power laser operation. This compact laser system wi...

We demonstrate a powerful diode-pumped blue laser source, consisting of a 7W diode at 807nm that pumps a Nd:YAG laser giving 1.6W with good beam quality at 1123nm, and a thulium-doped upconversion fiber laser. The maximum output power achieved at 481nm is 230mW. We also describe the behavior of a reversible loss which is generated in the fluoride fiber during high power operation.